1. Field of the Invention
The present invention relates to a light-emitting device using a light-emitting element that can produce fluorescence or phosphorescence by applying an electric field to the element provided with a film containing organic compound (hereinafter, also referred to as an organic compound layer) between a pair of electrodes and a manufacturing method thereof. Specifically, the invention relates to a light-emitting device in which light-emitting elements are arranged in active matrix form, and light generated in the light-emitting element is emitted to opposite sides.
2. Description of the Related Art
In recent years, research relating to a light-emitting device having an EL (electroluminescent) element as a self-luminous type light-emitting element has been advanced actively. The light-emitting device is referred to as an organic EL display or an organic light-emitting diode. Since these light-emitting devices have characteristics such as a fast response suitable for movie display, low voltage, and low power consumption driving, they attract an attention as a next generation display including new generation's cellular phones and personal digital assistants (PDA).
An EL element has an organic compound layer (also, referred to as an EL layer), an anode and a cathode. It is known that luminescence by an organic compound includes luminescence generated in returning to a ground state from a singlet excited state (fluorescence) and luminescence generated in returning to a ground state from a triplet excited state (phosphorescence).
One feature of an organic EL panel having an organic EL element is that it does not have a problem of viewing angle because the organic EL panel is a self-luminous type unlike a liquid crystal display device that requires a back light. Namely, an organic EL panel is more suitable for use out of doors than a liquid crystal display, and a variety of usages have been proposed therefor.
A polarizing plate or a circularly polarizing plate is used for a conventional organic EL panel having an organic EL element (for example, Reference 1: Japanese Patent No. 2761453). This is because external light is reflected on an electrode formed in a display portion and thus, the visibility of an image is reduced. In particular, in a state where no image is displayed, an electrode serves as a mirror surface, and the background could be reflected in the electrode. Further, even in a state where an image is displayed, problems such as reduction in contrast or difficulties in displaying black color are caused.
Laminated wave plates such as a laminate of films giving rise to a phase difference of a half wavelength for a monochrome color, which collectively serves as a half wave plate and a laminate of films giving rise to a phase difference of a quarter wavelength, which collectively serves as a quarter wave plate, and a circularly polarizing plate including such a laminated wave plate are generally used (Reference 2: Japanese Patent No. 3174367).